Existing positioning functions are based, among other things, on the use of the GPS system (Global Positioning System). GPS is an accurate position-determining satellite system. The system uses many satellites, where a receiver receives signals from several channels and from different satellites. The receiver determines the mutual phase position between direct sequences received from different satellites and calculates their positions in three coordinates from an equation system.
Positioning systems based on the GPS system also exist. The positioning information is transmitted with the aid of GSM technology (Global System for Mobile communication) or with the aid of some other cellular telecommunications technique (Mobitexe). This requires firstly capacity utilization in the GSM technique for short message services (SMS), and secondly it incurs costs in the GSM system and costs in the GPS system.